Opaque white 0013

[alfeze]

I am trying to use the beautiful bright white that is 0013 as a base for porcelain decals. To do the I am trying to get a flat simpler coaster 10cm Square as my base. I am using 0013on top of tekta clear. Both are 3mm. (previously I used white tekta over tekta clear but the white isn't bright enough to push the photos)
I have tried a number of variations of the full fuse schedule with your bubble squeeze. But am always getting a lot more bubbles trapped and causing the top surface to be very none flat. Especially compared to the tekta white with its lovely flat side.
I was wondering if there was anything special needed because of the difference in 'solidity/density' between the opaque white 0013 and the tekta clear? Especially with the opal colour being on the top... Initially I did smaller quarter size tests and had no problems with them. I have also tried various styles of cleaning including using bullseyes blue cleaner and none seem to make a lot of difference.
Thanks
Anne

[marykaynitchie]

What is your firing cycle? It the glass more than about 10 cm away from the elements? What size is the interior of your kiln?
Mary Kay

[alfeze]

I only have a relatively small kiln, fusion 7 style. so not possible to get away from the edges by 10cm. but I think that I am 10cm away from the top element.
I have had to run lots of temp tests using cones and a tester because it was firing hotter than the stated temps. also the raster the rate requested the less close it actually got to that rate.
But having rewatched the bubble squeeze video I think my rate to the 663C wasn't low enough.
I had it at 222 or 333 on some tests. which might not be close enough to 167.
thing is none of the bubbles are actually any larger than the ones shown without the powder. no more than 1mm in diameter, yet the top surface seems to have bulges at least 1mm High. as I say I don't get this much uneven top surface with tekta white on the top. maybe its my top temp that's not allowing the glass to flow and flatten back down because the 0013 needs more heat to do that bit? in c
150/300/0
500/660/30
300/797/10
annual.
the 500 is because of something else I was working on and I forgot to change it.
just a thought, is being 10cm always from the top element good or bad?
thankyou

[marykaynitchie]

Does your kiln have side elements? In any case, if you fire a large piece relative to the size of your kiln, the edges can soften substantially faster than the center of the piece, leaving you with glass that is sort of like a pie crust, sealed at the edges. Any air remaining on the inside has nowhere to go but up.

Mary Kay

[alfeze]

My kiln has side elements but they are very low. I used the powder method to try and eleviate the bubbles. I then upped the temp further eventually got almost smooth. 0113 definitely needed different temp to tekta white.

[alfeze]

typo in last post 0013 not 0113 needs more heatwork.

[marykaynitchie]

Thanks for reporting on what you tried, and the results!

Mary Kay